Bay Kennedy and Laguardia are about 50 minutes away...or were when I grew up there. Traffic might be worse now.
From a heat perspective, the farther east you go the better off you'll be, and the eastern sound has better sailing and more interesting destinations. Newport
is certainly the logical base as it's close to Providence and puts you within easy striking distance of the best cruising grounds...Block, Peconic Bay, Elizabeth Islands, Martha's Vineyard
Another option would be Sag Harbor. You could take the LIRR train to Kennedy or Laguardia, changing at Jamaica
, or to MacArthur airport (mid-island) which has grown in recent years and is quite usable.